Rotary blower



- Oct. 1', 1929. w, GREENv 1,729,826

Filed Feb. 10. 1926 5 Sheets-Sheet 1 Oct. 1, 1929. T. w. GREEN ROTARY BLOWER Filed Feb. 10, 1926 5 Sheets-Sheet 2 Oct. 1, 1929. T. w. GREEN 7 I 1,729,826

ROTARY BLOWER D Filed Feb. 10, 1926 5 Sheets-Sheet 5 59 i I 5;! 41 l 9 Q l K e a i' i U i M W m 70- a? 150 6 40 M N A Oct. 1, 1929. w. R E 1,729,826

' ROTARY BLVOWER Filed Feb. 10, 1926 5 Sheets-Sheet 4 Oct. 1, 1929. w, REE 1,729,826

" ROTARY BLOWER Filed Feb. 10, 1926 5 Sheets-Sheet 5 "null/"111111 \y/llllllllllllll 1 x III/Ill!III/IIII/I/IIII/I a 4 l Patented Oct. 1, 1929 UNITED STATES .PATENTFOFFFICE THOMAS W. GREEN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNbR TO THOMAS WIL- BRAHAM GREEN ENGINEERING- 00., OF PHILADELPHIA, PENNSYLVANIA,- A COR PORATION OF PENNSYLVANIA ROTARY BLOWER Application filed February A further purpose is to continuously seal the ends of a plurality of impeller blades, upon a plurality of revolving double concave rotor elements spaced about the circumference and free from intervening shafts. A further purpose is to provide rotor elements which are mounted upon removableheads carrying the shafts upon which they are rotated.

A further purpose is to provide three-Way connection at each end of the casing, combining the ends in supportlng and conduit functions.

' A further purpose is to provide two-stage compression where desired.

A further purpose is to shield the oil within the inside bearings of the blower from air pressure or air suction at the respective ends y venting the journal to atmosphere.

Further purposes will appear in the specification and in the claims.

Of the different forms of my invention I have elected to show but one main from with minor modifications selecting a form that is inexpenslve to manufacture, eflicient andv practical in operation, and which illustrates particularly well the principles involved.

Figure 1 is a front elevation of a blower.

embodying my invention.

Figure 2 is the end view of Figure 1. Figure 3 is a longitudinal section taken upon line 33 of Figure 2 or 33 of Figure 4. Figure 4 is a transverse section, taken upon line 4-4 of Figure 1 or line 44 of Figure 3.

'Fig'ure 5 is a longitudinal section taken 10, 1926. sin-m1 No. 87,294.

other end of the central shown in'Figure 8.

Figure 9 is a perspective View of either of the rotor valve units with end plates removed.

impeller from that Figure 10 is a horizontal central section of a two-stage blower.

Figure 11 is a vert-ical section taken upon the-line 1111 of Figure 10.

Like numerals refer to like'parts in. all figures.

Describing in illustration and not in limitation and referring to the drawings e,

The blower casing 15 comprises a main central portion 16 cylindrical at' 17 and 18 respectively above and below 'a centraliimpeller 19, lateral cylindrical portions 20 and 21 casing the rotor valves 22 and 23 and end portions 24 and 25 supporting the whole structure and carrying bearings for the shafts of the rotor elements which include the central impeller l9and the double concave valve elements 22 and 23.

The'impeller 19 is hollow to form radial The hub 30 of the impeller is fastened'to the main driving shaft 31 as by key 32 (Figure 5) and longitudinal radial Walls 33, 34, 35 and 36 from the hub divide the space around the shaft into four equal portions that areencased by outer walls'37 and 38 that make sealing fit with the rotor valve elements.

The impeller, considered as a whole, comprises walls that are not only symmetrical with respect to the axis of the impeller shaft,

but are also symmetrical with respect to each of two relatively perpendicular planes that intersect along the axis of the impeller shaft, and lie respectively longitudinally along the middle of the impeller blades 33 and 34 and gearing from the shaft 31 carrying the central impeller.

The separate heads facilitate manufacture by permitting free machining clear to the edges and allowing a choice of planing or v turning for the surfaces afiected when the rotor is made from cast metal and permitting free use of sheet metal if desired. At the same time the freedom from intermediate shafting providedby this construction makes the parts much more compact giving a larger internal lune sealing the diameter for the metal involved and shortening the over all width of the case as seen for example, in Figure 11.

The rotor valves 22 and 23'make the same number of revolutions as and synchronize with the impeller l9'and the concave lunelike curves .51, 52, 53 and 54 are formed to 7 make contacts seal against the outer ends of the central radial blades 33 and'34, the curves being those generated by the edges of the re- .volving blades 33 and 34 upon the synchronously revolving cylinders 22 and 23,

Referringto Figure 4 the concave curves 51 and 52 are formed to make contact seal with the outer endof the central impeller blade 33 and the opposite curves 53 and 54 of the respective rotor valves make corresponding contact seal against the outer end of the blade 34.

The cylindrical portions 55 and 56 of the diametral impeller and 57, 58, 59 and of the cooperating rotor valves have outside diameters that are preferably though not necessarily the same, (shown the same in the figures). v

The cylindrical portion of the impeller makes rolling seal with the cylindrical portions of the rotor valves, the cylindrical portion 55 of the central impeller sealing with the portion 57 of the rotor valve 22 and with the cylindrical portion 59 of the rotor valve 23 while in the same way the opposite cylindrical portion 56 of the central impeller seals respectively against arcuate portions 58 and 60 of the valve elements.

Cutting away the opposite portions of the rotor elements to provide contact seal against the respective ends of the central impeller blade makes it necessary to extend the wall of each conduit section at 61, 62, 63 and 64 respectively to seal against the ends or toes of the concave portions.

These extensions or wings are curved in such way that the toe of the concave portion makes contact seal against their outside until the circumferences engage after which there is a rolling seal.

The impeller and the rotor elements are symmetrical with respect to their own axes and the axes of the rotor elements are at equal distance from the axis of the impeller so that the rotor elements are similar and symmetrical with respect to their axes. For this reason the extended portion or wing sealing against the toe of one of the rotor elements will also make contact seal against the corresponding toe of the other rotor element.

Assuming the direction of rotation that indicated by the arrows in Figure 4 the end 33 of the impeller seals upon the concave porions 51 and 52 of the opposite rotor elements;

the outside of the wing or curved extension 61 makes sliding seal against the toe 65 of the left-hand rotor-valve (Figure 4) and subsequently against the toe 6,6 of the right-hand rotor valve element and in the same way the wing portion 62 seals against the toe 67" of one rotor and the toe 68 of the other, the wing 63 against the toes 69 and 7 O of the respective iz'gtors and the wing 64 against the toes 71 and Always the fluid through the machine travels radially inward to ultimate outlet along the advancing side of the impeller as at 7 3 and 74 respectively and the incoming fluid comes in along the receding sections 'of the central impeller at 7 5 and 76 respectively. This flow is continuous through the whole revolution of the impeller.

. As best seen in Figures 4 and 7 the volume sealed ahead of each advancing impeller, from the position shown in Figure 4 through that of Figure 7. to a position 180 from that ofFigure 4, continuously reduces, there being a seal at the left-hand end first from the position of Figure 4 by reason of engagement of the toe 65 along the wing extension 61 of the impeller and then by rolling engagement between the cylindrical portions 57 and 55 respectively of the rotor valve element 22 and impeller 19 and then of the toe 7 2 with the curve extension 64 at the other end of the impeller. e

All thistime the volume in the casing of the impeller ahead of the advancing blade 34 is diminishing and the air or other fluid included within this space is forced to escape through the passage 28" to outlet 77 l at the end of the impeller.

Simultaneously with decreasing volume ahead of the impeller blade 34 there is a corresponding increasing volume to the rear of the impeller 34 in the space from the rear side 7 5 of the advancing impeller 34 to "a continuous seal between the rotor element 23 and the bottom wall 38 of the central impeller.

This seal is between the toe 69 of the righthand rotor valve element along the curved wing portion63, then betweenthe circumferential portions 60 and 56.01? the rotor valve ram-a and impeller and then between the toe 68 and the extended portion 62 at the other end of the impeller until the position 180 from that of Figure 4 is reached.

As the volume back of the advancing blade has been increasing the air or other fluid has been continuously drawn into the space back of the advancing blade through the conduit portion 29 which is connected at 78 with the inlet end of the blower.

The opposite end of the impeller works exactly in the same way, the advancing portion 74 continually diminishing the volume within the casing ahead of the impeller 33 and. in-

.' creasing it to the rear of this impeller from a maximum just after the impeller is horizontal to a minimum when it is again horizontal, there being a change from a semi-cylindrical volume above the horizontal space to one below it and vice versa at the horizontal position.

The preferred form of the central imipeller 19 is shown in perspective in Figures 8, 8 and 8 The shell cylindrical at 55 and 56 respectively, and having extended wings at 61, 62, 63 and 64 is mounted upon a suitable hub 30 and this hub is connected or otherwise fastened to the central driving shaft 31.

Opposite conduit sections as 26 and 27 open at thesamc end into one of the end chambers 24 or 25 and the opposite corresponding ends of the other conduit sections open into the other end chamber as 24, because the advancing portions of the impeller blade are diametrically opposite to one another and likewise the receding portions of the blade are upon opposite sides of the shaft and these opposite openings at the same end are either outlet or inlet according to the direction of motion of the impeller.

Each of the conduit sections is open at one end into one of the end compartments 24 or 25 and closed at the other end, and adjacent sections are open at different ends and alternate sections at the same end.

One of the rotor valve elements is shown in perspective in Figure 9 without its end plates, which may be fastened to the valve element in any suitable way, as by screws or bolts at holes 79.

The rotor valve element in its preferred form is symmetrical not only with respect to its own axis but with respect to each of two relatively perpendicular planes that intersect along the valve axis.

The particular gearing between the shaft of the impeller and the blades of the rotor valve elements is subject to modification according to circumstance and whim of the purchaser or user.

In Figure 6 I showa spur gear keyed to the driving shaft 31 meshing with spurs 81 and 82 upon the respective shafts of the rotor valve elements.

There is some tendency for air pressure or air suction to act disadvantageousl'y upon oil within bearings of the rotor elements and to avoid. thisI preferably provide air ports- 85 (Figure 10) between the bearings and the suction or pressure chambers of the blower.

These ports may extend into the shaft and result in equalizing the pressure upon opposite sides' of the bearings so that there is no tendency for air leakage through the bearings which inwardly as by reason of suction fwithin the blower ad acent the hearing) or outwardly (as by reason of pressure within will be .no piping, while at the outlet or delivery end the piping is connected to-that one of the three outlets which is most convenient. In Figure 2T show the'air chambers 24 and 25 extending substantially the full width of the blower.

My bloweris well adapted to two-stagecompressionand 1' illustrate this in Figures 10 and-11'. In these figures the central impellers 19 and 19 of the first and second stages are relatively integral, being carried upon the" same hub 30..

The inlet 77 0f the second stage is the outlet 7 8 from the first stage.

The impellers and rotor valve elements at opposite ends are substantially identical with that of the form already described. A dividing web 89 separates the opposite sides of the rotor valve elements from one another and a corresponding groove 90, having a bottom concentric with the axis of the central impeller and an outer circumferential portion sealing against the outside circumference of the rotor valve element, separates the first and second stage portions of the central impeller.

The cylindrical casing 17 the impeller and valve portion can each be cast in one piece or fabricated from pressed metal portions, thus reducing the tool work and also the weight.

In View of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art to obtain part or all of the benefits of my invention without copying the specific structure shown, and I, therefore, claim all such in so far as they fall within the reasonable spirit and scope of my invention.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is a 1 a two cas ngs, a shaft carrying vof the impeller blades,

1. A two-stage blower comprising coaxial casings, coaxial double impeller blades in the both of the double impeller blades, arced sealing walls on opposite sides of the shaft spaced from each webs dividing the spaces inside of the arced walls into quadrants having inlet and outlet openings alternating at opposite ends, sealing wings at the ends of the arced walls, the outlets of the impeller in one casing connecting with the inlets to the impeller in the'other casing, wings at the edges of the arced walls and lunar arced rotor seals diametrically opposite in each of the two compartments sealing along their lunar surfaces with the ends of the impellers and along intervening arced surfaces with the arced walls of the impellers. v

2. An impeller casing, a shaft therein, an impeller blade on the shaft comprising two pairs of oppositely facing blades, oppositely extending one pair from the other parallel with the shaft, impeller end walls perpendicular to the shaft providing inlets and outlets upon opposite sides of the'blades intermediate Walls dividing the pairs into two parts perpendicular to the shaft and providing outlets from one compartment thus formed as inlets to the other and diagonally opposite placed lunar seals for the blades having double lunar concave surfaces, intermediate convex surfaces and end walls, intermediate walls cooperating with the blades to seal them and seal with the compartment division of them and driving means for the blades and seals timing them to register with each other.

THOMAS W. GREEN. 

